He is the disc jockey politician, a charismatic, fresh-faced entrepreneur who swapped the turntables and nightclubs of Antananarivo for a movement that this week has culminated in the ousting of Madagascar's twice-elected president.

So when Andry Rajoelina, 34, is inaugurated as Africa's youngest president today, expect a carnival of sound. His supporters have taken to blaring out Malagasy pop music to get crowds in the mood. This may even be the first African coup with its own soundtrack.

Images of the man this week have appeared incongruous: a sharp suit and baby face amid the sharpshooters in army fatigues, an unlikely alliance between the soldiers who have seen it all before and the 34-year-old who has got it all to come.

But behind the boyish good looks lies a ruthless ambition that has surprised many. "When he became mayor I had never heard of him before. But he was a charming person, he was easy to be around," says a former adviser to Rajoelina, who wished to remain anonymous. "In fact, he seemed quite shy and very polite. I never believed he could become what he is today - now it is very hard to know who this man really is."

Born to a relatively wealthy but unexceptional family and privately educated, Rajoelina was working the ramshackle clubs and bars of Antananarivo as a DJ by the time he was 20. "He would play wherever he could," says Liana Herisoa, chief editor of Rajoelina's privately owned television station. "For friends, in clubs, all over Antananarivo."

The snappy young DJ then moved into promoting other performers, and had soon set up his own radio station. And as Viva radio pumped out a hugely popular foot-tapping mix of international hits, pop music and love ballads, Rajoelina's profile began to rise.

Ultimately establishing himself as a successful entrepreneur at the helm of Injet, an advertising company, his appeal was instant. Just as that of former president Marc Ravalomanana - a self-made dairy tycoon - had been when he came to power after elections in 2001.

Early political aspirations were realised in Rajoelina's TGV (Tanora Malagasy Vonona - Young Malagasy's Determined) movement, the party platform from which he launched his mayoral campaign. Rajoelina soon earned himself the nickname TGV - as much a reference to his movement, as to the French high-speed train - a reflection of his unstoppable and feisty character.

The train finally arrived this week. With the support of a powerful core of rebellious troops, within an army that had tried to remain neutral until the bitter end, Rajoelina has spearheaded a dramatic regime change.

Always immaculately dressed, Rajoelina's rise has been as remarkable as it has been controversial. And his mayoral election campaign was an early indication of what he was capable of. He swept on to the political scene in December 2007, voted in as the mayor of the capital, beating the preferred candidate of Ravalomanana and sweeping the city's female voters off their feet.

In Antananarivo, Rajoelina made himself a superstar - a vibrant symbol of youthfulness and success.

His youth is a double-edged sword. At 34 he is still technically six years too young to hold the presidency, according to the constitution. But youth is a powerful commodity for those who want to see energetic efforts to bring about change. "We need someone young, we need someone who understands how we think," says Thomas, a restaurant worker in Antananarivo.

From the beginning, Rajoelina's relationship with Ravalomanana was defined by tension. Rajoelina positioned himself as one of the former president's most vociferous critics, tapping into a growing vein of anti-government sentiment. But despite his popularity in Antananarivo, Rajoelina has less support elsewhere in the country. Rajoelina has said he will hold presidential elections in 18 to 24 months.

Until then, Madagascar's new leader is going to have to work hard to convince the international community of the legitimacy of his army-backed rise to power.